Issue link: http://life-technologies.uberflip.com/i/460858
23 How should the serum be thawed? Serum should be thawed overnight at 2–8°C. If my FBS arrives partially thawed, can I still use it? All Gibco ® FBS is shipped frozen and packaged in dry ice, so it should arrive frozen. You can still confidently use FBS that is partially thawed, if at least two-thirds of it is frozen. Can I aliquot and refreeze the serum? Yes, after the overnight thaw, you can aliquot the serum into smaller, single-use aliquots and refreeze it. How long can I store thawed serum at 2–8°C? Serum should be used within 2–4 weeks when stored at 2–8°C. How can I minimize lot-to-lot variability? You can test each new lot to be sure that it works for your specific applications. Alternatively, our serum sales team can determine the most consistent, highest- performing serum lot available using the iMatch ™ Sera Lot Matching Tool. What sizes of packaging are available? Gibco ® FBS is available in 50 mL, 100 mL, 500 mL, and 1,000 mL bottles. How can I sample FBS or set up a reserve? Your serum sales representative will be happy to assist you in getting a reserve set up for a specific lot, or testing to see what lot may work best for you. Please go to lifetechnologies.com/fbs for more information. What is the shelf life of FBS? Most FBS products unopened and stored in a freezer have a 5-year shelf life. Also, you can refer to the expiration date on the bottle and the Certificate of Analysis for this information. Why does material precipitate in FBS upon storage in the refrigerator? Gibco ® FBS is not pre-aged. When stored at 2–8°C, various proteins and lipoproteins in serum (e.g., cold agglutinins, fibrinogen, vitronectin) may aggregate and form visible material or turbidity; however, this should not affect serum performance. We recommend that you store FBS at –20°C and avoid repeated freeze-thaw cycles. My FBS contains flocculence. What could it be? Flocculence may appear in FBS for a variety of reasons. The most common reason is the denaturation of serum lipoproteins. You may observe fibrin, a clot-forming protein, after the serum has been thawed. This should not affect the serum's performance. To remove flocculence, transfer the serum to sterile tubes and centrifuge the material briefly at 400 X g, and then filter the resulting supernatant along with your medium. Do not attempt to filter serum containing flocculence, as it may clog filters. Why is the measurement of oxyhemoglobin in serum important or informative? It is a quality indicator that reflects rapid collection and processing. Is the serum sterile? Fetal bovine serum is triple-filtered through 0.1 µm filters. Bovine serum is filtered through 0.2 µm filters. Is the serum tetracycline-free? Our limit of detection for tetracycline is 19.7 ng/mL, and tetracycline must be "undetectable" to pass inspection, but we cannot say that it is tetracycline-free. Find out more at lifetechnologies.com/fbs